C-shaped Canal Research Articles

Relationship of incidence of radix entomolaris and C-shaped canal in mandibular molars using CBCT: A multi-centre study.

This study aimed to evaluate the relationship of incidence between radix entomolaris (RE) in permanent mandibular first molars (FM) with C-shaped canal (CSC) in permanent mandibular second molars (SM). A total of 1015 cone-beam computed tomography (CBCT) images of permanent mandibular molars from Malaysian patients were collected retrospectively and analysed by researchers from seven dental schools in Malaysia trained in CBCT technology. The presence and absence of RE and CSC were scored as 'yes' or 'no'. The prevalence of FM with RE was 21.2% and SM with CSC was 37.9%. The co-occurrence of RE and CSC in the same quadrant was 6.5% (OR = 1.497, p = 0.014). Female, Chinese and samples from Eastern Peninsular Malaysia were associated with CSC in SM (p < 0.05). The increased appearance of CSC in SM when RE is present in FM makes it imperative for clinicians to be vigilant during examination and diagnosis to prevent potential endodontic mishaps.

Root Canal Morphology of Premolars in Population of Hyderabad, Pakistan: A Cone Beam Computerised Tomographic Analysis.

To investigate the mean tooth length and root canal configuration of human maxillary and mandibular premolars in the population of Hyderabad, Pakistan, using Cone Beam Computed Tomography (CBCT). Observational study. Place and Duration of the Study: Department of Operative Dentistry and Endodontics, Liaquat University of Medical and Health Sciences, Jamshoro, Sindh, Pakistan, from December 2022 to March 2023. Using retrospective analysis of CBCT scans, tooth length, the number of roots, and root canal configuration of 536 mandibular and maxillary premolars were assessed in the subpopulation of Pakistan. The data were analysed employing descriptive statistics, Chi-square tests, and One-Way ANOVA to determine the association between various factors and root canal morphology. Vertucci Type 1 (one canal) was the most common configuration in maxillary premolars, with frequencies ranging from 46.3 to 52.2%. The mean length of all 8 premolars ranged from 20.56 mm to 21.58 mm. C-shaped canal configurations were observed in a small percentage of maxillary and mandibular premolars, with C1 being the most common. No significant association was found between gender and canal configuration or tooth length, and in tooth lengths among different canal configurations. Vertucci Type 1 was the most common configuration in maxillary premolars, followed by Vertucci Type 4. Single-rooted premolars were more prevalent, while two-root configurations were less common. C-shaped canal configurations were observed in a small percentage of premolars, with higher frequency in mandibular premolars. Cone beam computed tomography, Dental anatomy, Endodontics, Premolars, Root canal morphology.

Micro-computed tomography evaluation of minimally invasive root canal preparation in 3D-printed C-shaped canal.

This study aimed to evaluate and compare the shaping abilities and minimum dentin thickness of minimally invasive rotary instruments via micro-computed tomography. Twelve 3D-printed C-shaped canal models from a mandibular molar were divided into two groups, and root canals were prepared with either XP-endo Rise (XR) or TruNatomy (TN) systems. Pre- and post-preparation evaluations included canal volume, prepared area and minimum dentin thickness. No significant differences were found in canal volume change (XR: 22.66 ± 4.28%, TN: 23.02 ± 5.10%), prepared canal area (XR: 31.86 ± 10.72%, TN: 30.26 ± 11.59%) and minimum dentin thickness (XR: 0.30 ± 0.05 mm, TN: 0.28 ± 0.05 mm) between groups (p > 0.05). The canal volume change in the middle third was significantly higher than that in the coronal and apical thirds (p < 0.05) in both groups. In conclusion, XR demonstrated comparable shaping abilities and minimum dentin thickness to TN in preparing 3D-printed C-shaped canals.

Prevalence and Classification of C-Shaped Canal and Radix in Mandibular Molars Using Cone-Beam Computed Tomography on Mexican Population.

The diverse morphological configurations in teeth present clinical challenges in root canal treatment, complicating instrumentation and irrigation processes, which can lead to treatment failure. Understanding anatomical variations, such as C-shaped canals and radix entomolaris, enhances clinical skills and improves long-term endodontic treatment success rates. Cone-beam computed tomography (CBCT) offers superior diagnostic capabilities over conventional radiography, enabling the pre-operative detection of root configurations and canal numbers, facilitating personalized endodontic treatments. A total of 2173 teeth of a Mexican population, including 1057 first mandibular molars and 1116 s mandibular molars, were studied using only CBCT to identify C-shaped canals and radix configurations of patients who were treated from 2018 to 2023 at the Department of Radiology at the Faculty of Dentistry, Juarez University of the State of Durango, Mexico. C-shaped canals were identified in 160 teeth, with a prevalence of 0.2% in first mandibular molars and 14.1% in second mandibular molars. The highest frequency was in the left second mandibular molar (3.7) at 14.8%. Gender differences were significant, with higher prevalence in females (27.3%) compared to males (13.3%). The most common C-shaped canal configuration was type C2 (39.3%). Radix entomolaris was found in 52 teeth, with a prevalence of 3.4% in first mandibular molars and 1.4% in second mandibular molars. This research on a Mexican population using cone-beam computed tomography (CBCT) highlights significant findings in the prevalence and types of C-shaped canals and radix entomolaris in mandibular molars for this population. The left second mandibular molar (3.7) showed the highest prevalence at 14.8%, followed closely by the right second mandibular molar (4.7) at 13.5%, with a significant difference (p < 0.001). We found a significant difference in the prevalence of C-shaped canals between genders (p = 0.004, OR 1.78). Additionally, radix entomolaris (p < 0.001) was more frequently identified in first mandibular molars to a significant degree. These insights underscore the importance of CBCT in diagnosing complex root anatomies, which can greatly enhance the success rates of endodontic procedures by allowing for more tailored and precise treatments for this population.

Correlation between root canal anatomy of mandibular incisors and premolars in Western Uttar Pradesh population of India - A cross sectional study

ABSTRACT Aim: This study aimed to evaluate the correlation between the presence of two canals in mandibular incisors and multiple canals in mandibular premolars in the Western Uttar Pradesh population of India using cone-beam computed tomography (CBCT). Methods: CBCT scans with 0.125-mm voxel size and 50 mm × 50 mm field of view of 800 patients were evaluated for the parameters; a number of canals, root canal configurations (according to Vertucci’s classification), unilateral/bilateral occurrences, and correlation between presence of two canal configuration in mandibular incisors and multiple canals (&gt;1 canal) in mandibular premolars. The data obtained were subjected to statistical analysis using the SPSS statistical program version 22.0 using the Chi-square test. The significance level was set as 5%. Results: According to the current analysis, the prevalence of mandibular incisors with one canal was 68.1% and two canals were 31.9% whereas in mandibular premolars prevalence of one canal was 71.5%, two canals were 27.2%, and three canals were 1.3%. The incidence of Vertucci type I canal configuration (68.1% mandibular incisors and 71.5% mandibular premolars) was more prevalent than the other types. The incidence of C-shaped canals was 2.6%. The prevalence of bilateral occurrence of the same canal configuration was 16.6%. A positive correlation was found between the presence of two canals in mandibular incisors with multiple canals in mandibular premolars (20.4%). Conclusion: The root canal morphology of mandibular premolar teeth of the Western Uttar Pradesh Indian population is complex. Two canals in mandibular incisors are frequently associated with multiple canals in mandibular premolars.

Cone-beam computed tomographic analysis of canal convolution in mesial root of mandibular second molars and a proposed new classification.

The aim is to evaluate the anatomical characteristics of mesiolingual and mesiobuccal canals in mandibular second molars particularly in terms of its exit direction, distance of confluence from the minor constriction, and the angle of confluence. The cone-beam computed tomography images of hundred mandibular second molars were analyzed. Endodontically treated teeth and those with anatomical variations such as C-shaped canal configuration were excluded from this study. The distance of the confluence from the minor constriction, angle of confluence, and the exit direction of the mesiobuccal and the mesiolingual canals were assessed. Data were analyzed using an independent t-test. The course of the mesiobuccal and mesiolingual canals beyond the confluence was towards the center of the root. The average angle of confluence was 32.75°-35.28°. The average distance of confluence from the minor constriction was 2.19 to 2.68 mm. The mesiolingual canal was straighter whereas the mesiobuccal canal had a tortuous course. Considering the results of the present study, a new classification has been proposed for the root canal morphology of the mesial root of mandibular second molars. The variation in the morphology of mandibular second molars highlights that the mesiolingual canal presented a mild curvature through and beyond the confluence when compared to the mesiobuccal canal which exhibited a tortuous course through the confluence.

Mandibular second premolar with C-shaped canal diagnosed with CBCT technology: case report with 24 months of follow-up

Mandibular second premolar with C-shaped canal diagnosed with CBCT technology: case report with 24 months of follow-up

The Assessment of C-shaped Canal Prevalence in Mandibular Second Molars Using Endodontic Microscopy and Cone Beam Computed Tomography: An In Vivo Investigation.

Background Understanding root canal anatomy variations, particularly C-shaped canals, is crucial for successful endodontic treatment. This study used clinical and radiographic methods to assess the prevalence and characteristics of C-shaped canals in mandibular second molars in Western Maharashtra. Materials and methods This prospective study was conducted in the western region of Maharashtra, India. The samples included patients requiring endodontic treatment for mandibular second molars. Clinical evaluation was conducted using a surgical endodontic microscope and cone beam computed tomography (CBCT) imaging. Inclusion and exclusion criteria ensured the selection of a focused and homogeneous sample. Data analysis included assessment of unilateral/bilateral occurrence, canal distribution, and cross-sectional characteristics. Results Out of 200 mandibular second molars, 7.5% exhibited C-shaped root canals, with no significant gender differences. Canal distribution varied across coronal, middle, and apical levels, with prevalent configurations being C1, C2, C3, and C4. No significant differences were observed in canal distribution based on root levels. No significant gender differences were found in the presence of grooves on the root surfaces. Conclusion This study provides valuable insights into the prevalence and characteristics of C-shaped canals in mandibular second molars in Western Maharashtra. Further research into histological and genetic aspects can enhance our understanding, leading to improved treatment strategies for complex root canal anatomy variations.

Evaluation of various obturation techniques with bioceramic sealers in 3D-printed C-shaped canals

This in vitro study compared various obturation techniques with bioceramic sealers for filling C-shaped 3D-printed replicas. A mandibular molar with a C-shaped root canal with a C1 configuration was obtained. After instrumenting with M3 Pro Gold files (United Dental, Shanghai, China) up to size #30/0.04, a CBCT scan of the tooth was taken. Sixty 3D-printed replicas of the tooth were created. The samples were obturated with EndoSeal TCS sealer (E. TCS; Maruchi, Wonju, Korea) or EndoSeal MTA (E. MTA; Maruchi, Wonju, Korea) (n = 30). The samples in each group were obturated with the following techniques (n = 10): (1) single-cone technique (SC), (2) SC with ultrasonic activation (UA), and (3) cold hydraulic compaction (CHC). Following incubation, the replicas’ apical, middle, and coronal thirds were inspected under a digital microscope, and the proportion of filling material and void were calculated. Also, the obturation time and sealer extrusion were recorded. Data were analyzed using ANOVA, LSD post-hoc, and the chi-square tests (α = 0.05). The results indicated that in the apical third, E. TCS-SC, E. TCS-UA, and E. MTA-UA had the lowest void percentage among groups (p < 0.05). In the middle thirds, samples obturated with E. TCS-UA showed a significantly lower void percentage among all groups (p < 0.05). However, in the coronal third, E. TCS-CHC showed the least void percentage (p < 0.05), followed by E. TCS-UA and E. MTA-CHC. The E. TCS-SC and E. TCS-UA were the least time-consuming methods (p < 0.05). Sealer extrusion significantly differed among the groups, with E. MTA-UA and E. TCS-UA showing higher incidence (p = 0.019). It was concluded that E. TCS-UA was the most convenient obturation technique. However, care must be taken when obturating the canals with high flow and ultrasonic activation near the vital anatomical landmarks.

Diagnostic accuracy of artificial intelligence versus dental experts in predicting endodontic outcomes: A systematic review

Abstract Introduction: In the rapidly evolving landscape of health care, artificial intelligence (AI) has emerged as a promising tool to enhance diagnostic accuracy across various medical disciplines. Within the realm of dentistry, one critical area of focus is endodontics, which involves the diagnosis and treatment of dental pulp diseases. This systematic review investigates the diagnostic precision of AI in contrast to dental experts when predicting endodontic outcomes. Materials and Methods: The review was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The review was registered on the Open Science Framework database. A systematic search was performed of the literature on the application of AI versus dental experts in endodontics. The search was conducted on PubMed, Scopus, Web of Science, and OVID until December 2022. The QUADAS-2 tool was used to evaluate the risk of bias. Results: The initial search retrieved 972 records, of which eight articles were included in the study. The studies reported application of AI for working length determination, periapical lesions, pulp and tooth segmentation, apical periodontitis, vertical root fracture, and C-shaped canals. QUADAS-2 tool revealed a low risk of bias in five out of the eight included studies. Conclusion: AI models demonstrated a notable increase in accuracy and effectiveness in endodontic diagnosis and treatment planning. These results suggest that the integration of AI technology in endodontic diagnosis and treatment planning has immense potential to serve as a promising aid.

External Validation of the Effect of the Combined Use of Object Detection for the Classification of the C-Shaped Canal Configuration of the Mandibular Second Molar in Panoramic Radiographs: A Multicenter Study

IntroductionThe purposes of this study were to evaluate the effect of the combined use of object detection for the classification of the C-shaped canal anatomy of the mandibular second molar in panoramic radiographs and to perform an external validation on a multicenter dataset. MethodsThe panoramic radiographs of 805 patients were collected from 4 institutes across two countries. The CBCT data of the same patients were used as “Ground-truth”. Five datasets were generated: one for training and validation, and 4 as external validation datasets. Workflow 1 used manual cropping to prepare the image patches of mandibular second molars, and then classification was performed using EfficientNet. Workflow 2 used two combined methods with a preceding object detection (YOLOv7) performed for automated image patch formation, followed by classification using EfficientNet. Workflow 3 directly classified the root canal anatomy from the panoramic radiographs using the YOLOv7 prediction outcomes. The classification performance of the 3 workflows was evaluated and compared across 4 external validation datasets. ResultsFor Workflows 1, 2, and 3, the area under the receiver operating characteristic curve (AUC) values were 0.863, 0.861, and 0.876, respectively, for the AGU dataset; 0.935, 0.945, and 0.863, respectively, for the ASU dataset; 0.854, 0.857, and 0.849, respectively, for the ODU dataset; and 0.821, 0.797, and 0.831, respectively, for the ODU low-resolution dataset. No significant differences existed between the AUC values of Workflows 1, 2, and 3 across the 4 datasets. ConclusionsThe deep learning systems of the 3 workflows achieved significant accuracy in predicting the C-shaped canal in mandibular second molars across all test datasets.

Morphological Variation of Mandibular Molars in Rohilkhand Population: An Original Research

ABSTRACT Introduction: In-depth knowledge of common and aberrant pulp morphology is essential for appropriate diagnosis and treatment planning before commencing root canal treatment. The radicular morphology of mandibular molars has been extensively studied. Considerable variation in the number of canals and roots found in these teeth has been reported. Aim: The purpose of this study is to investigate the root canal morphology of the mandibular molars among the Rohilkhand population using Dentascan. Materials and Methods: Dentascan images of mandibular molar were taken from 99 extracted teeth that were collected from the Department of Oral Surgery and Maxillofacial Surgery, Institute of Dental Sciences, Bareilly, and private clinics. The examination of root canal systems of the teeth was based on Vertucci’s classification. Results: The mandibular molar (n = 99) were taken. Out of the 99 teeth examined, three canals were seen in 60 (60.6%) teeth, four canals in 39 (39.4%) teeth, 3% had extra distal roots, and 6% with C-shaped canals. Conclusion: Among mandibular first molars, only 3% had three roots. Mesial roots of the first molar typically present with two canals and two apical foramina with type IV or II canal configuration. Most distal roots of the first molar presented with a type I canal configuration. The remainder were distributed mainly between types II, IV, III, and V. Among 99 mandibular molars, 6% had single C-shaped roots.

Root and canal morphology of mandibular second molar

Background: The mandibular second molar is the main chewing tooth and often suffer from pulp damage due to the misalignment of the mandibular third molar. In addition, it’s C-shaped root canal system is a challenge for endodontic treatment. This emphasizes the significance of tooth morphology and root canal system study which can contribute to anthropology, as well as Odonto-Stomatology. Purpose: The objective of this study was explore the morphology and root canal system of the mandibular second moalar in order to provide indicators dentistry applications. Materials and methods: Preclinical (in vitro) study was conducted on 48 mandibular socond molars which was collected in Thua Thien Hue province from December 2021 to June 2022. The teeth were measured externally and determine the shape of the roots. The canal system was examined with two methods including clearing technique and Cone Beam CT. Results: The average length of mandibular second molar was 20.37 ± 1.28 mm. 81.2% of teeth had one root, and 18.8% had two. The teeth with C-shaped roots accounted for 31.2%. The majority of distal roots possessed a simple type I (single canal) configuration. While the canal system of mesial roots was more complex which contained two canals, of which type I, II, III, IV were the most prevalent. C-shaped canal morphology was observed in 31.2% of the examined teeth. Conclusion: The root canall system of mandibular second molar was complex, the percentage of C-shaped canal was high (31.2%). There was similarlu results of two methods of clearing technique and Cone Beam CT in examining the root canal system of mandibular second molars. Key words: mandibular second molar, root canal system, C-shaped root, C-shaped root canal.

Cone-Beam Computed Tomography Analysis of the Root Canal Morphology of Lower Second Molars in the Croatian Subpopulation

The aim of this study was to investigate the root canal morphology of lower second molars in the Croatian subpopulation of the Zagreb region using cone-beam computed tomography (CBCT). We analyzed 3212 CBCT scans from the two radiology centers in Zagreb. The number of roots and root canals, the occurrence of C-shaped canals and additional roots were recorded. “C”-shaped roots were classified according to Melton classification. Canals in the mesial root were classified according to Vertucci. Lower second molars were found on 608 CBCT scans from a total number of 859. Among them, 78 (9.1%) had a “C”-shaped form. In the mesial roots, the frequencies of Vertucci types were: Type I in ninety-four cases (12.0%), Type II in three hundred and twenty cases (41.0%), Type III in six cases (0.8%), Type IV in three hundred and fifty-two cases (45.1%), Type V in three cases (0.4%), Type VI was found in four cases (0.5%) and Type VIII was found in one case (0.1%). Radix entomolaris and paramolaris were found in 29 (3.4%) lower second molars. The lower second molars in the Zagreb population show significant diversity in internal anatomy with a relatively high prevalence of “C”-shaped root canals and merged root canals in the mesial root.

Micro-computed tomography analysis of calcium hydroxide delivery efficacy in C-shaped canal system of mandibular second molars

BackgroundCalcium hydroxide [Ca(OH)2] is widely accepted as a biocompatible interappointment intracanal medicament. This study aimed to analyze the efficacy of Ca(OH)2 placement into the C-shaped canal system of mandibular second molars using the syringe method with and without lentulo spiral utilizing micro-computed tomography (micro-CT).MethodsTwenty-four extracted mandibular second molars were instrumented and classified into C-shaped floors (n = 12) and non-C-shaped floors (n = 12). Both groups were placed with Ca(OH)2 using the syringe system, then all teeth were scanned and cleaned, and placed with Ca(OH)2 again but with the syringe system followed by lentulo spiral and rescanned. The specimens were scanned using micro-CT to analyze the volume, volume percentage, uncontacted surface area, and uncontacted surface area percentage of Ca(OH)2 with the two delivery methods in the entire canal and at the apical 4 mm of the canal. Mann-Whitney test and Wilcoxon signed-rank test were used to determine the statistical differences among the groups.ResultsSyringe administration used in conjunction with lentulo spiral presented lower uncontacted surface area, a lower percentage of uncontacted surface area, larger volume, and a higher percentage of volume than syringe without lentulo spiral (P < 0.05). There was no significant difference between the C-shaped floor group and the non-C-shaped floor group (P > 0.05) in the Ca(OH)2 uncontacted surface area, volume, and percentages at different regions of canals and among different delivery techniques groups.ConclusionsThe lentulo spiral and syringe technique combination can increase the volume and contacted surface area of Ca(OH)2 in the C-shaped canal system of mandibular second molars.

Incidence of C-shaped canals in mandibular second molars in patients visiting Rehman College of Dentistry, Khyber Pakhtunkhwa (KPK), Pakistan

Objective: The objective of the study was to evaluate incidence of C-shaped canals in mandibular second molars using Cone Beam Computed Tomography. Study Design: Cross Sectional, Descriptive study. Place and Duration: This study was undertaken in Department of Radiology, Rehman College of Dentistry, Peshawar, from 15th June 2022 till 15th December 2022. Methodology: Cone Beam Computed Tomography scans of 60 patients of both genders between 18 and 60 years of age were studied for the presence of C-shaped canals in mandibular 2nd molars. Results were analyzed with the help of SPSS version 21. Chi-square was applied for comparison of male and female groups. Results: Cone Beam Computed Tomography scans of 60 patients of both genders between 18 and 60 years of age were studied for the presence of C-shaped canals in mandibular 2nd molars. Results were analyzed with the help of SPSS (version 21). Chi-square was applied for comparison of male and female groups (p &gt; 0.05). Conclusion: Incidence of C-shaped canal is high in patients with mandibular 2nd molars. Endodontists need to be vigilant for the existence of C-shaped canals and proper imaging of these canals is essential for successful endodontic treatment. Keywords: Root Canal Therapy, Molar, C-Shaped Canals, Pulp, Cone Beam Computed Tomography, Endodontic. How to Cite This: Rehman AZ, Alam S, Khan IA, Arbab KN, Khalid MD, Askar H. Incidence of C-shaped canals in mandibular second molars in patients Visiting Rehman College of Dentistry, Khyber Pakhtunkhwa (KPK), Pakistan. Isra Med J. 2023; 15(2): 70-73. DOI: https://doi.org/10.55282/imj.oa1373

Narrative literature review on the complexity of the internal anatomy of root canals

The intricate and highly variable nature of the internal anatomy of root canals poses significant challenges for effective endodontic treatments. The aim of the study was to interpret the complexity of the internal anatomy of root canals through a narrative literature review. This study adopted an exploratory methodology and was characterized by its observational and descriptive nature, analyzing information from a cross-sectional and retrospective perspective. An exhaustive evaluation of 25 articles was conducted on PubMed, Google Scholar, and Elsevier through ScienceDirect, from 2016 to 2023. This study revealed that a deep understanding of the internal root anatomy and its variations is essential for the success of endodontic treatments, highlighting the importance of advanced diagnostic techniques, such as Cone Beam Computed Tomography (CBCT), for identifying anomalies. It was found that anatomical variations, including C-shaped canals, lateral canals, and apical deltas, are more prevalent in posterior teeth. Moreover, anterior lower teeth rarely exhibit more than one root, with Vertucci type I classification predominating in their internal anatomy, which implies less complexity compared to posterior teeth. It concludes that success in endodontics critically depends on detailed knowledge of the internal root anatomy. The findings emphasize the need to apply precise diagnostic techniques and adapt treatment strategies to the specific anatomical complexity of each tooth, especially in those with more complex root configurations

Maxillary Second Molar: An Unconventional C-shaped Canal Configuration - A Case Report

Understanding the plethora of potential canal configurations is crucial for successful endodontic treatment, as it allows for optimal preparation of the canals by accounting for any deviations from the norm. This case highlights the rare occurrence of a C-shaped canal configuration found in a maxillary second molar, with a reported occurrence rate of only 3.8%. Although C-shaped canals are more commonly reported in mandibular second molars, recent literature has also observed such canal configurations in other teeth, including maxillary first molars, maxillary premolars, and mandibular premolars. The dental profession often faces a formidable task when dealing with the complex nature of C-shaped canal configurations during endodontic therapy; however, by anticipating and proactively managing these intricacies, dentists can avoid causing irreversible harm to the tooth.

Prevalence and morphology of different root canal systems in mandibular premolars: a cross-sectional observational study.

This study investigated the prevalence and morphology of C-shaped and non-C-shaped root canal systems in permanent mandibular first (PM1) and second (PM2) premolars using retrospective analysis of cone-beam computed tomography (CBCT) scans, and panoramic radiographs. CBCT scans from 2000 patients were screened for the presence of premolars with C-shaped canals and then assessed at three axial levels to determine the canal classification. The teeth were also assessed for Vertucci configuration, number of roots, and radicular grooves. Pre-existing panoramic radiographs were evaluated to identify features specific to PM1/2 with multiple canals or C-shaped anatomy. A total of 1576 PM1 and 1424 PM2 from 880 patients were evaluated. The overall prevalence of C-shaped canals was 2.2% (3.3% PM1, 1.0% PM2), with 49 (5.6%) patients presenting with at least one C-shaped mandibular premolar. There were 2.3 ± 0.6 and 2.4 ± 0.5 different classifiable cross-sections per tooth for PM1 and PM2, respectively. The sudden disappearance or bifurcation of a canal on panoramic radiographs was associated with the presence of multiple canals (P < 0.001) or C-shaped anatomy (P = 0.03). There was substantial variation in cross-sectional anatomy within and between C-shaped premolars, which will affect endodontic treatment planning. © 2023 Australian Dental Association.

Association of root morphology of mandibular second molars on panoramic-like and axial views of cone-beam computed tomography.

Knowledge about the anatomy and morphology of the root canal system is essential for successful surgical and non-surgical root canal treatments. However, precise assessment of the root morphology and anatomy is not often possible on two-dimensional radiographs. This study aimed to investigate the association of root morphology of mandibular second molars on panoramic-like and axial views of cone-beam computed tomography (CBCT). This cross-sectional study evaluated 1,231 CBCT scans of mandibular second molars obtained between October 2018 and February 2022 that were retrieved from the archives of a private radiology clinic. Panoramic-like images were reconstructed from the CBCT scans. The root morphology of mandibular second molars was classified on panoramic-like images as type 1, 2, 3, 4, or 5. The root pattern on axial CBCT images was classified into three types of single, double and C-shaped. The association of root morphology on panoramic-like and axial CBCT views was analyzed by the Chi-square test and Fisher's exact test at 0.05 level of significance. Of all, 62.7% of mandibular second molars were type 1; out of which, 97.3% had a double-root pattern on axial CBCT images. Also, 28.6% of them were type 2; of which, 92.6% had a double-root pattern. Moreover, 3.9% were type 3; of which, 47.9% had a C-shaped pattern; 0.9% were type 4, and 45.5% of them showed a single-root pattern; 3.8% were type 5 with 76.6% of them showing a single-root pattern. The prevalence of C-shaped canals was higher in females, and most C-shaped canals had a C3 pattern. Root morphology on panoramic-like CBCT views had a strong association with the root canal pattern on axial CBCT views. According to the results, mandibular second molars with a type 3 morphology on panoramic-like CBCT images are highly probable to have a C-shaped canal.